Telephone-exchange system.



E E. CLEMENT.

TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED MAR.27, 1905.

Patented Aug. 11, 191% 4 SHEETS-SHEET 1.

111.4 1 lll Invcnto;

APPLIGAII ON FILED MAR.27, 1905.

' Patented Aug. 11,1914.

4 SHEETS-SHEET 2.

Witnesses E. E. CLEMENT. TELEPHONE EXCHANGE SYSTEM. APPLICATION FILED MAR.27. 1905.

4 SHEETS-SHEET 3.

Inventor witnesses Patented Aug. 11, 1914..

E. E. CLEMENT. TELEPHONE EXCHANGE SYSTEM. APPLIGATIO'N FILED 111111.27, 1905.

1,107,1 33. Patented Aug. 11, 1914;

1 SHEETS-SHEET 4.

inventor WIUICBSES mmw "=12; BATE FFICE- EDWMD E. CLEIKENI, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSTGNOR, BY MESNE ASSIGNMENTS, T0 FREDERICK C. STEVENS, 0F ATTICA, NEW YORK.

TELEPHONE-EXCHANGE SYSTEM.

change systems, and particularly to semi-an tomatic systems. In such systems a calling subscriber is answered by an operator who connects him with a trunk-line leading toan automatic switching device whereby he may be connected with a wanted subscriber.

My present invention has for its object the production of such a systen'i which shall em ploy a common battery at the central oliice for all purposes, shall give the operators double supervision, shall provide for innuediate recalls i a calling subscriber, shall give automatic ringing a t'ter completing each connection, leaving repeated ringings to the operator until the subscriber answers. and shall generally embody all the desirable features and possibilities of a modern manual common battery system, including adaptability for registering measured service and party-line work.

In the present system I employ a bridged battery grounded on one side, as usual, so

that no possible objection can be raised on the score of possible electrolysis where a balanced ground is employed. I employ supervisory relays and control relays, and

make use of them for more than one purpose.

Many incidental objects and features are attained by and inhere in the invention, which will sufliciently appear from the following detailed description and claims.

In the present system I use the switches shown and described in the patents to Keith and Erickson granted March 13, 1906, and numbered 815,176 and 815,321, the latter ap plyin .to Figure 3 of this application, wherein the selector switch is used, and the former applying to Fig. 4 wherein the connector switch is used.

My invention is shown in the accompanying drawings, wherein Fig. 1 shows a subscribefs station with a transmitting device. Fig. 9 is a similar diagram showing the central oflice end of a subscribers. line-circuit, the ford-circuit. and

Specification. of Letters latent'.

Application filed March 27., 1905.

Patented Aug. 11, 1914. Serial No. 252,305.

trunk-jacks leading to the automatic switches. Fig. 3 shows a first selector switch. Fig. 4: shows a connector switch and the central office end of a subscribers line-circuit.

Referring now to Fig. 1, I have shown a subscribers station with apparatus usual in common battery systems, consisting of the transmitter T, receiver R, hook H, ringer Q and condenser C. In addition to this I have shown the transmitting device, which consists of the following: the number-wheel (L which transmits impulses corresponding to theten thousand nume 'al of the line wanted, the number-wheel d, which transmits, impulses corresponding to the thousand numeral of the line wanted, the number-wheel (P, which transmits impulses corresponding to the hundred numeral of the line wanted, the number-wheel d, which transmits impulses corresponding tothe ten numeral .01 the line wanted, the number-wheel (P, which the wire 110 through the contacts (5 and number 2 side of the line is grounded through the contacts d (13 wire 113, contacts (5 (Z wire 114, contacts (Z and cit. This ground energizes the line-relay at central which in turn operates the line-signal. The number-wheel (Z is released by the ma gnet (Z and while operating breaks the linecircuits 1' and 2 through wires 110 and 111 and contacts and d". This nuinbenwheel after it has run down releases the numberwheel d, which while operating makes and breal is the ground on line number 1, through the wires 110, 123, and contacts d and The number-wheel (1* in running down cuts on the ma met (15, which controls the number-wheel This number-wheel while operating makes and breaks the lines 1 and 2 through the wires .110, 111, 124:, contacts: and ai After the number-wheel (Z has run down it cuts on the magnet (Z which in turn contrcls the number-wheel d. T115 wheel while operating makes and breaks the lines 1 and 2 through the wires 110, 111, 125, 126 andccontacts d and ti. The numberwheel dfiafter it has run down releases the number-wheel 0Z which while operating, grounds the line number 2 to wire 111, and contacts (1 and al These number-wheels While being set engage the pawls di d, d 03 and d respectively, but do not make an break the contacts which they control, the pawls yielding while the wheels are being set. But while the wheels are running down to transmit the impulses, they make and break the contacts which they control. The last i'iuniber-wheel when run down, closes the contacts a? and d which close the talking-circuit of the telephone. This talking-circuit is open while the various impulses are being transmitted to prevent the subscriber from receiving annoying clicks. Thislatter feature is shown and described in my allowed application. tie-rial No. 295,058,

19, 190 telephone stem and apparatus, an-las respects this f ire this application is division of the application mentioned.

Referring to Fig. *2, number 1 side of line from the subscribers station terminates in a ground through the contacts a, n or the cut-off relay N. Line number 2 from the subscribers station terminates in the linerelay M, connected to battery through the contacts a, n" of the cut-off relay N. The inner contacts a a of the cutoff relay N, terminates in. the springs j and y" of the jack J. One winding of the cut-oif relay N 'is connected to ground, the other terminal being connected to the spring j of the jack J. The spring 9' of the jack J is connected to battery, as is also the thirnble j The Wires leading to the springs j, and j" are led to multiple-contacts e 2 2 in the connector switches, by the wires 11, 14 and '13, respectively. The lamp m is controlled by the line-relay M.

The cord-circuit consists of the following: the answering-plug P, calling-plug P, supervisory or repeating relays S and S, controlling-relay pilot-relay S busy-backrelay E and the indicating magnets s and s, which control the registering device, answering supervisory lamp 3 and calling snpervisory lamp 8 The tip p of the answering plug P, connected to the strand 16, and the tip p of the calling plug P, connected to the strand 18, are separated by condenser C, the sleeve 2 of the answering plug P, connected to the strand 17, and the sleeve p of the calling plug P connected to the strand 19, are separated by the condenser C. To the third conductor of the answering plug I", one terminal of the relay S is connected by the wire 22, the other terminal being grounded. One terminal of the relay S is connected to the third conductor p of the calling plug. P by the Wire 4:2,the other terminal-being connected to the main battery bus-bar and from there to battery. One terminal of the lamp .9 is connected to front contact .9 of the relay S", the armature 8 being connected to battery, the other terminal of the lamp is connected to the back contact 8 of the relay S b the wire 25, the contact being grounde It will be seen that the lamp 3 will burn when the relay S is deenergized and the relay S energized. The magnet 8 is controlled by the relay S, making and breaking the contacts s and s, the magnet .9 being connected to the contact .9 through the wire 27, contacts a, 8 of the relay S and wire 28. The magnet s is operated by the making and breaking of the contacts a, s of the relay S, the magnet .3" being connected to the contact 8*, through the wire 26, contacts 8 s, of the relay S and wire 32. The relays S and S are alled-the repeatrelays because they are actuated directly by the impulses from the subscribefls transmitter and in turn actuate other relays. One terminal of the relay S is connected to the strand 16 by the wire 20, the other terminal being connected by the wire 29 to the contact .9 and by the contact 8 of the relay S to battery wire 35. The upper contact a is grounded, so that when the relay S is energized and attracts its armaturcs the winding of the relay S is connected to the ground side of battery. The relay S is connected to the strand 1'? by the wire 21 and by the wire 30 to the contact a by the contact s of the relay S to ground. The upper contact a is connected to battery through the wire 35, so that when the relay S is energizedand attracts its armature, relay S is connected to the free side of battery. The battery is reversed by the relay S for controlling the magnets in the transmitting device, which will appear later on. The lamp 8 is connected to ground by the wire 43 to the contact of the relay S by the wire elf), and it will be seen that this lamp will only light when the relay S is energized. Tlie generator or busy-back G is connected to the back contacts a and c of the busy-back relay E. The contacts a and e are connected to the strands l6 and 17, respectively, by the wires 36 and 37. One terminal of the relay E is conncclcd to the back contact 8 of the relay S by the wire 38, the contact 8 being grounded. The other terminal of the relay E is connected to the contacts 76 and I0 of the ringing key K, and by the wire 41 to contacts a and 8 of the relay 8, these contacts being coin nected to the sleeve 1) of the calling plug P by the wire 4:6. It will be seen that in order to connect current from the generator or the busy-back G, the relay S and the relay S will have to be energized and free side of battery connected to the sleeve 79 of the calling plug P. This only occurs when the testrelay in the connector switch finds the line called busy, but this operation will be explained later on. The strand 19 is connected to the spring is of the ringing but-ton or the key K by the wire 47, the contact In v U. The continuity of the strand 18 is' connected to 'battery by the wires 48 and 35. In the strand18 there is inserted a test key broken when the springs u and u. are connectedtogether for the purpose of testing a trunk to'see whether it is busy. After the test is made the continuity of the strand 18 is completed through the contacts u and M. 'This test can be in the form of any standard operation which will give the operator the characteristic click in the car when a trunk is found that is busy. The trunk-wires leading from the first selector switch terminate in the springs j, j, the ring j and the jack J by the wires &9, 50 and 51, respectively. Referring now to Fig. 3, I havcshown the first selector switch Z, which consists of the following: the vertical relay S normally connected to trunk-wire 49 to the side switch 2 by the wire 55 and to ground by the wires 61 and 59, the rotary relay S being connected to; the trunk-wire 50 through the side switch a bythe wire 56 and. to ground through the wires 60 and 59. The vertical magnet s is operated by relay S through the normally closed contacts 8 and s of the private relay S One terminal of the winding of the relay S is connected to the contact 5- of the rotary relay S;

by the wire 68, the other terminal of the 'winding being connected to battery through the wires 64 and 57 the normally open contact 8 of this relay is connected to the contact as of the. back release relay X by the wire 63. One terminal of the relayX is connected to the blade of the side switch a", the other terminal being connected to the private wiper? by the wire 70. One terminal of the release magnet IV is connected to battery by the wire 57 and the other terminal being connected to the contact a? of the relay X by the wire 69. One terminal of the rotary magnets is connected to the secend point on the side switch '2 by the wire 66, and the other terminal being connected to battery by the wire 57. The wire 51 lead- The wipers z, 2 2 and 2? engage the con" tacts leading to the wires 490, 500, 511 and 510, respectively, which in turn leadto the connector switch Z in Fig. 4.

Referring now to Fig. 4, I have shown the connector switch Z, which-consists of'the following: vertical relay 8", rotary relay S busy-back relay E. pilot relay V, ringing of the relay E. wires 105 and 81 to contact 8 and armature s -of the relay S to ground. The supervisory relay S is connected to the trunk-wire 72 by the wire 102 and to battery by the wire 82: The supervisory relay S is connected to the trunk wire 73 by the wire 99 and to ground by the wire 106. The ringing relay Y controlled by the rotary relay S is connected to the contact 3 by the wires 102, 85, by the wire 68 to the wiper 2, the resistance coil F is also connected to this'wiper-Z and to battery by the wire 89. This places the ringingrelay Y and'the resistance coil F in multiple. The trunk-wires 490 and 72 are separated by theconden'ser C the trunk-Wires 500 and 73 .are separated by the condenser C r The test relay ,X' is normally connected across the wipers 2 and 2 through the following path: wire 92, contacts y and 3 of the ringing relay Y, wire 96, contacts '0 and o of the. pilot relay V, wire 74 to wiper z", the other terminal by the wire 91, contacts '0 and o of the relay V, wire 75 to wiper 2 The release magnet W is normally under control of the test relay through the following path: ground, wire 97, contacts '0 and o of the relay V, and wire 98 to contact 02 of relay X, the contact 3: is onnected to battery by the wire 90. The relay X becoming energized would in turn energize. the release magnet W which would restore the switch to its normal position. The springs controlled bythe relay V are held in their normal position by'the latch r. This latch bethe springs assume other positions and are restored to their normal position again by the arm 2 that is attached to the spindle 2, when it assumes its normal position. The ringing relay Y is under the control of the rotary relay S and is'operated when the Wiper 2 is at rest on the line wanted, leading to theline cut-off relay and the armature of the relay S being attracted in closing the contacts 8, 8""; The vertical magnet '8 is operated by the vertical relay S when it is actuated and makes and breaks the contacts s and 8*. The magnet s is connected to the contact 8 by the wire 84, and the Wire 86 to the conta ctr"v ,,'z.' and 0 of the relay V. The rotary ;magnet.';s is op erated by the rotary relay S-- wh in it is actuated and makes and breaks the ontacts s and '8, "the magnet 8 being connected to 110 ing attracted when the relay V is energized the front contact 8- by the wire 85, by the wire 87 to the contacts 41. '0 of the relay V to ground, the contacts 8 s of the relays S and S being connected to battery by the wire 82. The busy back relay E is controlled by the test relay X, one terminal be- -ing' connected to battery and the other terminal being connected by the wire 103 to the contact 02 of the relay X, the contact a be: ing connected to ground. The relay X upon becoming energized, upon finding a busy line attracts its armature, closes-the contacts 0: and m which energizes therelay P through the contacts 8 s of the relay tor.

apfound and secured the pilot relay .V becomes S ,'Fig. 2. It will be seen thatthe relay E becomes locked through the winding of the relay E, and is under control of the opera- It was stated before that the release magnet W wasnor nally under control of test relay X, but after the wanted line is energized, releases the latch and its springs assume different positions. The contact '0 leading to the release magnet'VV and the contact '0 leading to the contact a: of the test relay X were broken, and the contact a is now in connection with the contact v leading to multiple contacts in the first selector switches, Fig. 3, by the wires 83 and 511; It is also connected to the contact 8 of the relay S by the wire 83. This places the release magnet under control of the operator, as will be described later on. The latch relay V in releasing opens the contacts 12 2) and o whieh'disconncct the wires 87 and .86, leading to the magnets 8 s? from round. It also disconnects the test relay h 0 a l X from ts normal position across the wipers 2 2 by breaking the contacts 11 and 'v and e '0. It also connects the trunkwircs 72 and 74: by the following path':-contacts 3 and y of the ringingrelayY, Wire 76, e and e to 74. It also connects the trunk-wires 73 and by the following path: contacts 3 and y of the ringing relay Y,wire 77, contacts o", 'v 'of the relay V to wire 7 5. The subscriber or the operator, in ringing energizes the ringing relay Y. This relay when energized, opens the contacts y and y, y and y" breaking the wires 72, 74, 73 and 7 5, and closes the contacts y*, y, y, 3 placing generator current from the bus-bars 94, 95 to the Wires 74 and 75- leading to the wipers 2 and 2 and fromthere to the called subseribers station. The contacts in the ringing relay Y are broken in this manner topreveiitcurrent from flowing back overthe wires 723ml 73 to the calling subscribers station. The relayS is controlled; by the operator, and in turn controls the release of both the first selector switch and connector switch, as will be described later.

One terminal winding is connected by the wire 101 to the contacts 8 ands of the relay S, to ground by the wire 106, the

other terminal winding-connected ,tothe wire 510 whichterminates in multiple banks engageable with the wiper z of the first selector switch, Fig. 3. The wiper z is connected to the thimble j of thejack J, Fig. 2, by the wire 51. The contact .9" of the relay S is connected to'battery by the wire 82,.

and the contact 8 is connected to the con.-

tact s of .the relay S by the wire it .will be noticed that the winding oi the relay Y connected to the vwiper 2 by the wirel88 is deenergized when the relay S is deenergized. For this reason the resistance coil F is also connectedto the wiper a? so as to provide means for holding up the cut-ofi' relay N of the called line.

The operation of my system is as follows: The subscriber inmaking acall sets his number-wheels corresponding 'tothe number of the line he wishes to call. Referring to-Fig. 1, in setting the first numberzwhee'l (Z the magnet cl is connected to line 1 by the wire 115, contact d d and wire 110. -In setting the last number-wheel d he grounds the line 2 by the following path. Wire 120, contacts a and 4Z wire 113, contacts 01 and d wire 114, contacts d and d" to ground. In setting'the last number-wheel d, the contacts (1 and d are broken, andthe talking setconnected by the wires 120 and121 is disconnected. The ground placed on line No. 2 energizes the line-relay M, Fig. 2, through the contacts n ,n*, of the cut-01f relay N. The line-relay M thereupon attracts its armature, and lights the line lamp m. It will be noticed that the magnet di is connected to the number 1 side of line to v ground, and that number 1 side of'line at central is grounded directly through the contacts n, n of the cut-0fl' relay N, so it' will be seen that the magnet d is not affect: ed by the act of signaling the central ofiice, and the number-wheels of the transmitting, device remain set. The operator perceiving. the signal, inserts the answering-plug-P into. the jack and the following connections and disconnections take place: The contacts i and j" are closed' which energizes the cutofi" nelay'h', which attracting its armatures breaks the contacts 11. and-n, n and n, disconnecting the line-relay M and the ound.- The'line-rlay M being disconnects extinguishes the line lamp m. The eontacts'n, a and air: '12, are closed, connecting the line a. It also connects the line 2 to the spring j by the wire 4. The insertion of the plug P places battery in reversed order on the line-wires l and 2, through the repeating relays S and S. Free side of battery is now placed on line No. 1 through the following path: armature n and contact n of the cutofl relay N, wire 3, spring j, tip p, strand l6, wire20, relay S, wire 25), contacts and s of the relay S wire to battery, and grounded side of ,battery is placed on line No. 2 by the following path: contacts a, n of the cut-off relay N, wire 4, spring j, sleevep, strand 17, wire 21, relay S, wire 30, contacts 5 s of the relay S to ground. Free side of battery now being placed on No. 1 side of line, the magnet d becomes energi'zed and attracts its armatures, breaks tl contacts (Z 65 which disconnects ground from No. 2 side of the line, lifts the latch (Z which releases the first numberwheel d". This number-wheel in running down makes and breaks lines No. 1 and 2 by the contacts (i and (Z controlled by the pawl d. The making and breaking of the lines 1 and 2 actuates the relay S" the number of times corresponding to the ten thousand numeral of the line wanted. The relay S making and breaking its contacts opcrates the vertical magnet 8 whose armature engages a pawl and moves a number-wheel or indicator to the number corresponding to the number of impulses sent in over No. 2 side of the line; the magnet s is controlled bythe relay S through the following path: battery B, wire 65, contacts 8 and a of the relay S whose armatures were attractenergized uhtil the impulses began to come in over No. 2 side of the line. The magnet a at once made one step, and to provide for this contingency it, as well as the magnet s, is provided with one false movement, that is, in making the first step instead of indicat g a numeral they indicate Zero. After vnumber-wheel d has run down it opens the contacts d, o disconnects the magnet 1 opens the contactsd d to prevent and being again connected to the No. 2 of the line. It also lifts the arm d carrying a pawl, which releases the second number-wheel d running down makes andbreaks a ground across So. 1 side of the line, through the contacts d and (2, w res 123,110. Wh le tneseimpulses are going in over No. 1 side at T u o 0r aiel ne, he. 2 sld'e ofthe l ne remains This number-wheel in clear and the relay S remains deenergized. The impulses. comlng in over No. 1 side of the line corresponding to the thousand numoral of the line wanted, actuate the relay S which in turn operates the magnet s a corresponding number of times. The magnet s is controlled by the relay S by the following path: battery B, wire (35, contacts 5, s of the relay S wires 21 and 31, con tacts s, s of the relay S, wire 28, contacts s, a of the relay S wire 27, magnet ,9 to ground. The magnet .sin operating moves its armature which engages a pawl and moves the number-wheel or indicator to the number corresponding to the thousand numeral of the line wanted. There now appears before the operator on her indicator the numbers corresponding to the ten thousand and thousand numerals of the line wanted. In the meantime, number-wheel d after it has run down closes the contacts (1, cl, cutting on the magnet d through the wire 117, the contacts a? and being closed when the number wheel 11 was first set. The magnet (Z is now connected from ground to the linc-wire No. 2, but remains deenergized as the relay S, Fig. 2, is connected to the grounded side of battery, and so the last three nun'iber-wheels remain set. The operator by means of the numbers appearing in her indicator knows the ten thousand and thousand numeral of the line wanted. She thereupon places the calling-plug P into a. trunk-jack leading to that group, after first using her test key U to see that the trunk not busy. This test is accomplished in the ordinary manner and gives the operator a click in the car if the trunk is busy.

In placing the plug P into the trunk-jack J the relay S one terminal of which is connected to battery through the wire 35, is energized -by the following'pat-hz'wire 42, third conductor 2?, j wire 51, contacts 2 z to ground, these contacts being controlled by the cam .2 on the spindle a in the first selector switch Z, Fig. 3. The relay S being energized, the following connections and disconnections take place: The contacts 8 s are connected, closing the circuit of the lamp .3 causin it to glow. The contacts s and s leading to the busy back-relay E are closed, but the means for closing its circuit or energizing it are not yet p rovided. The contact s is disconnected from the contact 3 and connected to the contacts, thus connecting the relay S to the grounded side of battery. The contact 9 spring j, wire 50, first contactv of side tact s and connected to the contact 5 thus disconnecting the magnet s and connecting .the contacts 8" of the relays to the strand 19. Battery now being reversed through the windings of the relays S, S,1nagnet d, Fig. 1 is energized in series with the relay S by the following path: wire 116, contacts d, 03, wire 11?, contacts 65 (Z wire 112, line wire 2, contacts a n of the cut-off relay N, wire 4, spring 7",sleeve p, strand 17, wire 21, relay S, wire 30, contact 8 8, wire 35, battery B. The magnet d becoming energized lifts the latch (2 containing the pawl and releases the numbenwheel d which in running down makes and breaks lines Nos. 1 and 2 by the contacts d, d, controlled by the pawl d. The relay S, Fig. 2, re-

'mains energized through the winding of the magnet d, Fig. '1, while the impulses are coming in affecting the relay S. The number-wheel d in running down transmits impulses corresponding to the hundred numeral of the line wanted, actuating the relay S. The making and breaking of the contacts 5 8 now send in impulses to the vertical relay S Fig. 3, by the following path: battery B, wire 65, contacts a, s? of the relay S wire 24, and 31, contacts a, .9 wire 28, contacts s 8 of, the relay S wire 33, strand 18, tip p, spring 3' wi 19, first'contact in the side switch 2 wire 55, vertical relay S wire 61 and ground. The relay 8 corresponds to the makes and breaks caused by the relay S, and in turn attracts its a1anature correspondingly, and operates vertical magnet a by the following path: ground, contact 8 a, wire 67 contact 8 and s of the relay 8, wire 58, magnet 3 wire 57 and battery. Vertical magnet s in operating causes the spindle z carrying the wipers 2' 2 2 and 2 to step up in a vertical direction to the row of contacts leading to a connector switch containing the lines corresponding to the hundred numeral of the line wanted. While the numkhf ivheel (Z was running down and transmitting impulses to the relay* S the relay 8 was energized and attracted its armatures. Just as the number-wheel (Z runs down there is a momentary break before the magnet d is cut on to line-wire 2. This momentary break allows the armatures of the relay S 'to fall back the contacts 8 and 8 closing, places battery through the rotary relay S by the following path: battery B, wire 65, contacts s 8 of the relay S wires 24, 31, contacts 8 and 8 of the relay S, wire 32, contacts 8 and 8 wire 34, strand 19, sleeve switch a", wire 56, relay 8", wires 60, 59 and ground. The relay S becomes energized, attracts its armatures and energizes the relay S by the following path: ground, contacts 5', a, wire 68, relay S", wire as, wire 57 and battery. lhe relay S being ,ing path; the nurnbcn energized causes the side switch to take one step, which cuts on the relay S and the relay X is series to the wiper lit also connects the" rotary magnets s to ground through the side switch 2"". The rotary magnet now being cut on causes the spindle 2 to rotate and to continue to rotate until thewiper s finds a contact that is not busy, that is to say, not grounded. So long as it is in connection with a grounded cont-act the relay S remains energized, being connected to the wiper .2 in series with the relay X. The relay X being ]o\\'-wound does not become sufliciently energized to attract its armatures. The instant the wiper e finds a contact that is not busy, that is to say one free from grounds, the relay 8'" becomes deenergized, moves the side switches one more step; the rotary magnet s is then disconnected and the spindle ceases to rotate and the wire 49 leading from the spring j of the trunk-jack J, Fig. 2, is connected to the wiper 2 by the wire 53, and the trunk-wire 50 leading to the spring ,1" of the trunlejnck J, Fig. 2, is connected to the wiper by the wire 54. The relay S is discoiniectcd from the wiper 2 and the relay X- connected from the wiper .2 direct to ground. The vertical relay 3 and rotary relay S are now disconnected from the trunk-wires 49-50, respectively. The instant the spindle 2 began to rotate the cam .2" opened the contaets and 2", which disconnected ground from the wire 51 leading to the ring j of the trunk-jack J, Fig. 2. and from thereto the third conductor 71', wire 12, relay S wire 35, battery B. This ground being removed, the relay S becomes denergiaed and battery is reversed through the windings of the relays S and S so that battery is now howing over the wires 1 and 9 as when the call was first answered. The reversing of this 15 ,ttery causes. current from the free side to flow. out on line No. 1 through the winding of the relay S and grounded side to flow out on No. 2 side of the line through the wind ing'of the reia The (new e cl, Fig. 1, is now ct'inneeteii to the line F v the followheel at haviiig run down: contacts of", of, wire 118, contacts (1, d, wire 117, contacts (11 of, and wire 112. Grounded battery now being on No. 2 side of the line this magnet a not affected, and the last two numbenwheels a? and (Z remain sei. ll hen the spindle ceased torotate and the wipers rested on contacts leading to a trunk in the desired group, the relay S, Fig. 2, was again energized by a ground through i" e following path: Fig. 4, wire .106, contacts 5 s of the relay S. wire 101. relay 5'), wire 510, Fig. 3, wiper .2 wire iii in l" 2, j wire 42, relay S, wire battery. The relay S thereupon being 0 again reverses battery on the iine, L. battery is sent out on No. 1 side of the line through the relay and tree side of battery is sent out on No. 2 side of: the line through relay S. Free side of battery now being on No. 2 side of the line the magnet d lifts the latch (5' and releases the number-wheel (Z This number-wheel in running down makes and breaks the lines 1 and 2 0y contacts (Z d, controlled by the pawl These impulses corresponding to the ten numeral of the line wanle'd actuate the relay S, the relay S being energized through the magnet (5 while these impulses are coming in. The making and breaking of the contacts in the relay S according to the ten numeral of the line wanted operate the vertical relay 8 in the connector switch a, Fig. 4, by the following path: Fig. 2, battery B, wire 65, contacts 8 a, relay S wires 24 and 31, contacts 8 s of relay S, wire 28, contacts s 8 of relay S, wire 33, strand 18, p, j, wire 4.9, Fig. 3, wire 53, wiper 2, wire 490, Fig. 4%, wire 78, relay S, wire 80, contacts a, s of the relay S to ground. The relay S in turn operates the magnet a correspondingly by the following path: battery B, wire 82, contacts a and a of the relay S wire 84, magnet 8 wire 86, contacts e o 0 of the relay V and ground. The operating of this magnet 8 causes the spindle e carrying the wipers a", z, .2 to step up in a vertical direction to the row in which the desired line is located.

Referring now to Fig. 1, after the nunr. her-wheel d has run down the contacts a,

pi are opened and the magnet o disconnected, the latch (Z containing the pawl is lifted and the number-whecl a released. No. 1 side of the line is clear and. the relay S becomes dccncrgized. The impulses are sent in over the No. 2 side of the line by the number-wheel 7 running down making and breaking the contacts (.Z and controlled by the pawl (6. These makes and breaks send in impulses from ground over No. 2 side of the line actuating the relay S corresponding to the unit muneral of the line wanted. The relay S by making and breaking its contacts operates the relay S in the selector switch Z, Fig. 4 .'by the following path: Fig. battery B, wire 65, contacts s of the relay S wires 2t and 81, contacts a and s of the relay S, wire contacts 8 and 8 of the relay S wire 34, strand 19, p, j, wire Fig. 3, continuation of wire 50, wire bet, wiper 2 wire 500 and in Fig. at, wire 79, relay S wire 104, contacts and c of the relay E, wires 105, 81, contacts a, of relay 8 to ground. he relay S" in turn operates the magnet s correspondingly by the following path: bat tery B, wire 82, contacts a and s of. the relay S", wire 85, magnet 5, wire 8?, contact o and n of the relay V. The armature of the magnet .9 when operated causes the spindle carrying the wipers 2 2 and 2 to rotate and come into contact with the line desired. These wipers pass rapidly over the contacts a, .2 and .2, the latter of which are grounded through the cutoll' relays N. The period of engagement of the wipers with these contacts is of such sho-t' come to rest on the desired contacts, the relay S having permanently pulled up through the decnergization of the relay S, current now energizes the ringing relay Y through the cut-oil relay U by the following path: battery it, wire 82, contact 5*, 8, wire 85, relay Y, wire 88, wiper z,,contact 2 wires 13 and 15, cut-oil relay N and ground. The relay Y when energized attracts its armature and the following con nections and disconnections are made: The contacts 1 and 3 are closed, energizing the relay V by the following path: battery B, wire 90, contac's 3 and 3 wire 93, relay V to ground. The contacts g Q are broken, disconnecting the test relay X which was normally connected across the wipers s and 2 The contact y is disconnected from the contact 3 which opens the wire 72 and is connected to the contact y leading to generator by wire 94. The contact 3 is disconnected from the contact 3/ breaking the wire 73 and connected to contact 3 leading to the other side of generator by wire 95. Generator current is now connected across the Wipers :5 and 2 by the following path: wire 74-, contacts r and '0 wire 76, contacts yf and 5 wire 94 to one side of generator,

and by the wire75, contact u and a, wire 77,, contacts 1 1 wire 95 to the other side of generator. lVhen the relay V was energized it tripped the latch n and the following connections and disconncctions were made: Contact -11 was disconnected from the contact c and connected to the contact '0.

The contacts was disconnected from the the contact 4) and connected to the contact 72*. Contact '0 was disconnected from the contact r and connected to contact o. This takes the release magnet W from under control of the test relay X and places it under direct' control of the operator by the following path: ground, release magnet WV, wire 97 contacts e and W, wire 83, contacts s and s of the relay S", wire 100, contacts a, s of the relay 8, wire 82 to battery B. It is controlled by the operator in the following manner: So longas the calling-plug P is in the trunk jack J; relay S i energized and the contacts a and a are broken and the circuit of the release magnetvv" is open. The-relay S is deenergized when the called subscriber has answered by the relay 9% being energized and attracting its armatures opening the contacts s and s which opens the circuit of the relay S", but at the same time the contacts s and 8 are broken and the circuit of the release magnet W remains open. The contacts 21 2; and o of the relay V are also broken and the magnets s and 8 are disconnected.

Referring again to Fig. 1, the numberwheel (Z after it has run down closes the contacts (Z and'd, which closes the talking-circuit through the wires 120 and 121,

and the calling-subscriber is connected to the called subscriber by the means of the cord-circuit Fig. 2; first selector Z, Fig. 3; connector Z, Fig. 4. It will be noticed that ringing current is sent to the called subscriber automatically by the last numberwhcel running down in the calling-subscribers transmitting device.

Referring now to Fig. it will be seen the operator has doubie'supervision over the connections by means of the lamps a .9 The lamp 8 remains lighted so long the relay S is energized. It becomes dergized when the called subscriber has an red in the following manner: The superrelays S, S are energized when the e '1 subscriber takes down his telephone in answering, and their armatures are attracted. In .the relay S the contacts .9 s arebroken. This opens the circuit of the relay S Fig. 2, which thereupon lets its armatures fallback extinguishing the lamp 8 Battery is also reversed through the relays S and S, but does not affect anything, as all the number-wheels at the sub scribcrs station have run down. The contacts leading to the magnets s and s are again connected in the relay S but remain open by the contacts 8 and a of the relay '8 being broken. The contacts 8 and a of the relay S being broken the armatures of elays S and S being attracted during Satin-n.

nected by the contacts 5 and s lay S being broken after. ringing. "tance coil F connected permanently i by the wire 89, is connected to the wiper a, and holds up the cut-off relay N wl the ringing relay Y is disconnected. Suppose the called subscriber did not answer the ring of his telephone, which was at first done automatically by the last number-wheel in the calling subscribers set, the operator having supervision over this called subscribers line notices the lamp a continuing to gl she at once knows the subscriber t answered his telephone, and by pressing to lever 01: the ringing-key against the contact is, which is connected to battery by the wire 35, she energizes the relay 55 in a connector switch Z, which attracts its armature, closes the contact a and a, which energi the relay.

The ringing relay Y, Fig.

a switch Y as in the former case and ringing current is againsent out over he called subscribers line. This ringing can be repeated until the subscriber answers. When the called subscriber removes his telephone, he closes the circuit through the relays S and S which attract their armatures. The contacts 8, s and s are broken and the vertical relay S and the rotary relay S are disconnected. The contacts .9 and a of the relay 8 are broken to prevent the release magnet W" getting current, ,the contacts 8 and s which control the circuit of relay S are also broken allowing its armature to fall back. The moment the contacts a and 8" are broken the relay S in Fig. 2 becomes dcenergized and the lamp 8 extinguished, notifying the operator that the called subscriber had answered. At the end of the conversation both subscribers hang up their telephones, causing the lamps s and s" to glow, thus notifying the operator that she may take down the connection. The opcr atornalvays pulls the trunking or calling plug P first, so as to provide for a recall by the calling subscriber in case there happens to be one, the reason for which will be described later. In taking down the answering-plug P the relay N becomes dcenergizcd and the line-relay M is again connected to line ready for another call. In taking down the calling-plug P. the circuit of relay S, Fig. 4, was broken, it thereupon bccomes (lei ncrgized and its armature falling back closes the contacts 8, s, which places battery on the contact 8 of the relay S. The relay S being deenergizcd on account of the calling-sub scr ber having hung up his telephone, the contact 8 is in connection with contact 8 and battery is furnished the release magnet W, which'bccoming encrgized restores the connector switch Z to its normal position.' The spindle a carrying the arm 2 descends and places the contactsprings of the relay V under control of the latch 22. The contacts 8 and 8 of the relay S also connect battery to the relay X, Fig. 3,,by the following path wire 511, wiper wire 70, relay X, sidc-switch 2 wire 71 to ground. This relay attract ing its armature closes the contacts 02 and m", which closes the circuit of the release magnet 3V, and restores the switch 2 and all its parts to their normal position.

Referring now to a recall by the calling subscriber that is if he wishes to call for another numberat once, the following operation takes place: The calling subscriber at the end of a conversation desiring to be connected with another party, immediately sets his number-wheels as in the first case. The release magnet controlling the first numher-wheel connected to No. 1 side of the line to gro l the plug P still being in the trunk Y o i per iscry s i. not ali'ected and the lamp continues to burn and the magnet rolling the, first number-Wheel of the unsinitting v ice is also not t-Li'lQCt8d. At

ict rc 1 amperviscrjr lamps are urin and the *perator taking" down the galling piug l Sb, the relay 'Wnose arm ur-cs t nereupon fall back, reversed through the relays Sf the relay Setracts its armature and at once eating'ulslies the lamp if. operator that the answering supervisory lamp 8 is entingriislied, upon Wi idrawing the calling-plug once knows there is a recall and looks to her indicator for the number as in the case, These nui'nbers conic-in exactly the same manner as first described and the operation is iden tieal, so there is'no need-of further description. 1

Suppose the line called for was busy when the "Wipers 2 and 2 came into Contact with the terminals e and 2 leading to the Wires 3 and aof the line circuit. ln this case there would be bridged battery on these Wires furnislied by the relays S and S in the operators cordrircuit. The test relay X is normally connected across the Wipers e and 2 through the contacts and y" or" the relay Wire contacts c and c of the relay V, wire to wiper a, other terminal being connected by wire 91, contacts c and c the ey wire '75 to the Wiper 2 The test relay X wmild then become energized, G attract its armature, close the circuit of the release ma Va by the following path: battery '33, .re contacts 01 and 0;, Wire LA 98, contacts c, of the relay V, W re 97,

CAD

magnet W to round. The release magnet i5 l being energized would restore the switch to its normal position. The contacts 02 92 being closed complete the circuit of the back relay E by the following pathfnf, m Wire 103, ll, to battery. The relay X. only attracts its armature momentarily," means provided to lock the relay E. This is accomplished by the following path: battery B, Winding E, contacts 6, c, wire 59:}, and in Fig. 3,.wire 500, Wiper 2 wire 54, Wire 56,- and in Fig. 9, 7), Wire @6, contacts a, 3 of the relay 55 wireall, contacts la and k of ringing key K, Winding oi"- tbe relay E, wirell contacts 8, e oi? the relay S to ground- The relay E then remains locked through the relay E, which in turn becomes energized and at tracting its arinatures closesthe contacts 6, c and c", c", and connecting generator cnn. rent for a busy-bacli' signal "to the strands l6 and 17. respectively, and can there to the calling subscribers line, notifying him that the line called for was busy. He thereupon hangs up his telephone and deenergmes the relays S and S, and causes the laipp 8 to glow, which notifies the operator, w 0 thereupon takes down the connection. j Taking down the calling-plug P, she opens the circuit of the relay S, Fig. 4, and lets its armature fall back, closing the contacts 8 ends, which places battery on the re-, lay X in the first selector switch Z, Fig. 3, by the following path: battery B, wire 82, contacts a and a, Wire 100, contacts 8 and 8 otthe relays 5, Wire 511, and in Fig. 3, Wiper 2 wire 70, relay X, side' switch 2, Wire 71 to ground. The relayX thereupon becomes energized and attracting its armature closes the contacts 8 and a, which closes the circuit of the release magnet W, this magnet becoming energized re- 5 stores the selector switch Z to its normal position.

While I have illustrated and described the impulse transmitter at the substation With five wheels-and three magnets, it shouldof course be understood that with slight alteration one magnet will govern all the wheels in practice, the showing herein being simplified for diagrammatic purposes.

While I have stated that my present inyention is particularly applicable to semiautomatic systems, there are certain features thereof which may be employed in any systern. Such for example is the arrangement of the latent signal sending device or impulse transmitter at the subscribers station.

There must'be impulse actuated signaling or connecting devices to respond to such a transmitter, but obviously these may be of any desired type without affecting oi changing this point of invention. 1 shall therefore claim such a combination broadly, ir-

respective of the type of central ollice connecting devices.

Having thus described my invention what I claim and desire to secure .by Letters Patcut is:

1. In a telephone exchange system, a subscribers line, a substation connected to said line, a talking set at the substation, an impulse transmitter also at the substation comprising a'pair of make and break Wheels and contacts governed thereby, said Wheels adapted to be set so as to make and break said contacts a determinate number of times, a magnet and a retainingdevice controlled thcreby for holding the first wheel when set, a retaining device for the second Wheel controlled by the movement of the first Wheel, a linesignal connected tothe linenormally and adapted to be operated when the Wheels are'set Without operating. the said magnet at the substation, a connective circuit adapted to be brought into con nection with said line, a receiving device associated with said circuit and adapted to be affected by impulses from the substation, and means becoming operative in making connection with the line to change the course of current throughthe line circuit so as to energize the retaining ma et at the substation, substantially as described.

2. In a telephone exchange system, a sub scribers line, a substation connected to said line, a talking set at the substation, an impulse transmitter also atthe substation comprising a pair of make and break wheels and contacts governed thereby, said wheels adapted to be set so as to make and break said contacts a determinate number of times, a magnet and a retaining device controlled thereby for holding the first'wheel when set, a retaining device for the second wheel controlled by the movement of the first wheel, a line signal connected to the line normally and adapted to be operated when the wheels are set without operating the said magnet at the substation, a connective circuit adapted to be brought into connection with said line, a receiving device associated with said circuit and adapted to be affected by impulses from the substation, and means becoming operative in making connection with the line to change the direction of currentthrough the line circuit so as to energize the retaining magnet at the substation, substantially as described.

3. In a telephone exchange system, a subscribers line, a substation connected to said line, a talking set at the substation, an impulse transmitter also at the substation comprising a pair of make and break wheels and contacts governed thereby, said wheels adapted to be set.so as to make and break said contacts a determinate .number of times, a magnet and a retaining device controlled thereby for holding the first wheel when set, a retaining device for the second wheel controlled by the movement of the first wheel, a line signal connected to the line normally and adapted to be operated when the wheels are set without operating the said magnet at the substation, a connective circuit adapted to be brought into connection with said line, a receiving device! associated with said circuit and adapted to be affected by impulses from the substation, and means becoming operative in making connection with the line to reverse the cur; rent through the line circuit so as to energize the retaining magnet at the substation, substantially as described.

v 4. In a telephone exchange system, a subscribers line, a substation and a central station connected to said line, an impulse transmitter at the substation adapted to "be set to make and break or ground the circuit according to a predetermined code, a magnet controlling the impulse transmitter and when the latter is set, connected from one side of the line to ground, a connective terminal and a line signal associated with the line at the central station, a main battery thereat grounded on one side and normally connected across the line with its ground on the same side as the substation controlling magnet, a central station circuit adapted to be brought into connection with the line, and means thereby becoming operative to reverse the battery on the line, so as to direct current through the said controlling magnet and release the substation signal de vice, substantially as described.

5. .In a telephone exchange system, a subscribers line, a substation and a central station connected to said line, an impulse transmitter at the substation adapted to be set to make and break or ground the circuit according to a predetermined code, a magnet controlling the impulse transmitter and when the latter is set, connected from one side of the line to ground, a spring jack and a line signal magnet associated with the line at the central station, a main battery grounded on one side and normally connect ed across the line with its ground on the same side as the, substation controlling magnet, a cut-ofi" relay connectedto the jack and adapted when energized to-cut oif the line signal magnet and reverse the battery connections, a plug and cord circuit adapted to cooperate with the line jack, a signal receiving device associated with the cord to respond to the substation transmitter, and means to energize the cut-off relay when the plug is inserted in the jack, substantially as described.

, 6. In a semi-automatic telephone exchange system, a line circuit, a SlllJSttllilUll and a central station, an impulse transmitter at the substation comprising a plurality of elements adapted to be set to transmit successive numbers, a retaining magnet for said transmitter retaining each number as set, and grounded from one side or the other of the line as the numbers are set and go in, a spring jack for the line at the central ofiice and a cut-off relay associated therewith, a cord circuit and an answering plug, an impulse receiver associated with the cord and adapted to respond to one or more of the numberstransmitted, a trunk circuit and an automatic switching device connected therewith, multiple line terminals of subscribers linesin said switch, means to connect the cord to the trunk; a main battery grounded on one side and normally connected through the cutoff relay contacts to the line with its ground on the same side as the normal connection of the substation controlling magnet, means operable when the plug is inserted in the line jack for energizing the eut-ofi' relay to remove the normal bhttery connections, and reversed battery connections simultaneously llli astablished, whereby the substation magnet is energized and one or more numbers transmitted; togetherwith means becoming operable on connecting the cord with the trunk to again reverse the battery connections, thereby again to release the substation transmitter to send controlling impulses to the automatic switch to move the latter into connection with a wanted line terminal, substantially as described.

7. In a telephone exchange system, subscribers lines and central ofiice apparatus for interconnectin them, latent signal cirsaid central. ofiice cuit changers at t e substations each com* posed of a plurality of transmitting ele- -ments with magnetic controlling means permitting operation of the elements to send successive number groups, said magnets bein successively connected from one .side of tie line and the other to ground, apparatus comprising' automatic signal and switching devices operating successively to connect a line calling by a plurality of steps in accord ance with the numbers transmitted, to the line wanted, and means operated in making the successive steps to change or reverse the battery connections from step to step so as to produce'successive operations of the substation number elements in proper order, substantially as described. a

8. In a telephone exchange system, a subscribers station and'latent signal impulse transmitting device with a talking set, said 'signal transmitting device comprising means for setting up the transmission of a plurality of roups of impulses and thereafter transmitting the same successively, together with means operated by the setting means to disconnect the talking set and to maintain such disconnection until the impulse transmitter has transmitted all the groups and finished its operation, substantially as described.

' .9, In a telephone exchange system, a sub" scribers line and a substation impulse transmitter, a line jack and signal at a central 'ohice, trunk lines at the central ofiice equipped with automatic connector switches having subscribers line terminals, an operators cord circuit for intgrconnecting the said subs'criberfs line with any of said trunk lines, thereby placing the automatic switchmg means under control ofthe subseribe'rs transmitter, means for differentiating the calling from the called end of the connected circuit thus formed, and for supplying current thereto independently, supervisory rescribers station with a telephoneand an impulse transmitter, a line circuit therefrom terminating in a spring jack at a central ofiice, an operators cord circuit with a terminal plug codperating with said jack, a trunk indicating device associated with said cord circuit, means controllable in makin connection with the line to place said indicating device. under control of the subscribers transmitter, a selector switch connected to a trunk, and magnetic operating means therefor,-means for connecting the subscribers line through the cord and trunk with said switch, means operable upon making said connection to remove the cord indicator from the subscribers control and transfer the same to the selector switch magnetic devices, trunk connections from said selector switch to connector switches containing subscribers terminals and also having magnetic control, with means operable upon effecting connection through a selector switch to a desired connector to remove the selector magnets from the subscribers control and transfer said control to the connector controlling magnets; a ringing relay and means where scriber, and means controlled by the operator to actuate the said ringing relay for repeated ringing if the wanted subscriber does not immediately answer, substantially as described.

11. In a telephone exchange system, line circuits, operators cord circuits and trunk circuits with automatic switches connected thereto, means initiated by an operator in response to a call from the subscriber to effect a connection through the aut -riatic switches to a wanted line, said switches being under the control of the calling subscriber in selecting and connecting with the wanted line, together with means under the control of the operator for releasing said switches at the termination of a conversation, substantially as described.

12. In a telephone exchange system, a subscribers line terminating in a spring jack at a centralofiice, a trunk line, means initially controlled by an operator in response to the ,subscribers call for connecting his line with 1 said trunk 11118, an automatic switch, controlled thereafter by the subscriber'and operating to connect said trunk-line with a wanted line, and means controlled by the operator for disconnectimgz; the lines, substantially as described.

switch also controlled by the calling subscriber for effecting the connection of the trunk line with the desired line, and means under the control of the operator for effecting a restoration of the switch to its normal condition at the end of the conversation.

In testimony whereof I have afiixed my signature in presence of two Witnesses.

, EDWARD E. CLEMENT. Witnesses H GH M. STERLING,

JAMES H. MARK. 

